Plausibility: How much information is enough?

An area that has come under increasing scrutiny is the issue of what information must be present in a patent application to make it “plausible” to the skilled person that the invention does what is claimed.

Most agree that an application must demonstrate at least some level of exemplification, in order to show that it “works” and thus justify the monopoly right received.

However, patent applications having incomplete disclosures can arise when the desire to file early (whether to gain an advantage over competitors, or to pre-empt a publication) means there is not enough time to generate adequate supporting data.

Recent case law before the European Patent Office (EPO) and UK courts has focused more attention on how much information is considered “enough” to persuade the skilled person as to the existence of an invention.

The answers have sometimes provided an unpleasant surprise for the patentee.

The most recent development in this story has come from the EPO, the practice of which has long suggested that the key is that information in the application as filed must be sufficient to render it plausible that the invention solves the problem it purports to.

Post-filed evidence could then be used to supplement this initial information.

Case study

A decision by the board of appeal (T 0488/16) published in July 2017 has shed further light on how the EPO proposes to treat the issue of plausibility, and the balance between post-filed data and the information in the application.

The decision in T 0488/16 related to European patent 1,169,038, covering Bristol-Myers Squibb’s (BMS) dasatinib anti-cancer product.

The specification contained details of the structures of a broad family of compounds, to which dasatinib belonged, as well as a statement that examples had “been tested in one or more … assays”.

No data directly illustrating the kinase inhibition key to the therapeutic utility of the compounds was shown.

The patent was opposed, and revoked for lack of inventive step, with the opposition division of the opinion that the lack of data in the specification meant that it had not been plausibly demonstrated that the compounds were protein tyrosine kinase inhibitors suitable for treating cancer.

BMS appealed against the opposition division’s decision and submitted post-filed evidence of the activity of dasatinib, along with expert witness declarations, in its appeal.

Having considered the submissions, including the post-filed data, the board of appeal decided they were not sufficient to overturn the position taken by the opposition division. Accordingly, the patent remained revoked.